Then flossing thread is used for cleaning between adjacent teeth a single strand is usually held in tension between the fingers of a person whose teeth are being cleaned, or else between a pair of spaced mechanical elements projecting from a common supporting handle. In either case, the common practice is to insert a single strand between the adjacent teeth and to rub it up and down against the adjacent side of one tooth while pulling in one direction against that side, and hhereafter against the adjacent side of the other tooth while pulling in the opposite direction against the other side.